The credit industry, traditionally, has a cascade of debt collection tiers. Once one tier fails to collect, they'll sell on the debt. The value of the debt (asset, to the collector) decreases drastically as we travel down the tiers. The "quality" of collectors also decreases. Business models that depend on illegal practices, betting on inadequate enforcement. Trial preparations that depend on 99% certainty of defendant not showing up. Most of the debt might be arbitrarily imposed interest and fines to nonresponsive "clients." The lawyer present may not have paperwork, or even know the companies' originally owed.
Financial assets like bad debt portfolios scale and bundle wonderfully, so there's no floor. There are multi-million dollar packages out there selling for $1000. An enterprising individual might take a blind chance. Apply creative means of collecting 1.3% of total debt. Maybe you offer 90% settlements. Maybe impose 500% fees and sell on. Maybe you specialise in deceased estates, acquire high morbidity debtor lists, and use systemic timing to advantge. Maybe you rebunde such that specialists can have a crack.
Anyway... At the copyright trolling end of this game, I'd make a distinction between "photographers," "rights holders" and the "copyright biz." What some shady lawtech startup does to monetize a copyright portfolio owned by their pay-per-performance client... "Photographer" is not really an active category within this structure.